1. Field of the Invention
The present invention relates to a process for treating cellulosic fibers. The cellulosic fibers prepared from such a process may be used to prepare a handsheet or other structure that may be used in a disposable absorbent product intended for the absorption of fluids such as body fluids.
2. Description of the Related Art
A variety of chemical treatments of cellulosic fibers are known. An example of a well known chemical treatment of cellulosic fibers is a mercerization process wherein cellulosic fibers are treated with, typically, sodium hydroxide under suitable conditions to convert the cellulose from its native form into a more thermodynamically stable, less crystalline form. Because the mercerized cellulose is less crystalline and more amorphous, the mercerized cellulose is generally more accessible for further treatment with additional reagents.
Known processes for chemically treating cellulosic fibers typically disperse the cellulosic fibers in a solvent, such as an aqueous solution. However, it has been generally recognized that in order to ensure proper mixing of the cellulosic fibers and whatever chemicals are being used to treat the cellulosic fibers as well as to ease the bulk transport of the treatment mixture, such known processes must have the cellulosic fibers present in the solvent at a low consistency. Such processes therefore generally result in the use of more of the solvent in which the chemical treatment takes place, or the chemical treatment agent being used, than would ideally be needed, thereby increasing the costs of manufacturing the chemically treated cellulosic fibers. Additionally, the use of sodium hydroxide, or other caustic agents, typically requires specialized handling procedures as well as recycling processes to ensure that such materials are not discharged to the environment.
It is therefore an object of the present invention to provide a process for the preparation of treated cellulosic fibers in which the amount of solvent and chemical treatment agents used in the process is minimized.
It is also an object of the present invention to provide a process for the preparation of treated cellulosic fibers in which the cellulosic fibers are essentially uniformly chemically treated.
It is also an object of the present invention to provide a process for the preparation of treated cellulosic fibers in which relatively high temperatures may be used.
It is also an object of the present invention to provide a process for the preparation of treated cellulosic fibers which will significantly reduce the costs of manufacturing.